Not able to concentrate sometimes while walking

hi,
i am having a problem since past 7-8 months, i am not able to concentrate during walk, i feel like the road is shaking . this generally happens when i think about it.
i consult with physician , he told me to visit eye specialist,then the eye specialist said that my eye sight is fine you will visit ENT(ear, nose , throat) specialist.
then i thought it was in my mind and nothing happen to me . but it started again.
All time its in my mind , i try to avoid but again it happens .
sometimes when i lean against wall and thought about it then i feel that the wall is shaking. I am really worried aboout it.

i wan to clear that i'll have marijuana in my college days some 2 and half years back and i have reduced the cigarretes also.
daily iam going to Zym and have a sound sleep of 6-7 hrs .
please do some needful suggestion . shall i visit neurologist or phyciatrist because i am really worried about this problem